Hello christo and Andreas,
You are actually talking about the same coaches...., but let me add a few minor corrections.
The mixed luggage-post coaches (ΔΕφπτ and not Δφπτ, as Andreas said correctly) were initially 5, numbered ΔΕφπτ 1321-1325. They were later renumbered as 50 73 91-60 821-825. However the last one, 50 73 91-60 825-8, was destroyed in Doxaras accident on 16/01/1972 and that's why it is not mentioned in later lists.
As Andreas said, the ΔΕφπτ had two doors on each side. Two for the post compartment, and two for the luggage compartment.
The six post coaches were initially numbered Εφπτ 1641-1646. Their first renumbering according to UIC-RIC was to 50 73 90-60 901-906 (not Εφπτ 901-906), and finally all of them, probably except 90-60 901-8, were renumbered again to 50 73 90-60 882-886. (Since then, some of them were renumbered once more, as they were converted to maintenance and auxiliary vehicles.)
This time, with one door per side.
Both of these classes, ordered via contract 1037/50, were built by "Industrie Stabiensi Mecc. & Navali - AVIS - C/mmare di Stabia" in 1952, and their design was quite similar with the pre-war ΔΕφστ 1311-1314 (mixed luggage-post) and Εφστ 1635-1638 (post only) - 1926 Austrian coaches.